Fan and propeller



Dec. 21,1926. 1,611,717

La R: BUSHYAGER FAN AND PROPELLER Dec, 2l 1926.

L. R BUSHYAG ER FAN AND PROPELLER Filed March 11. 1926 2 Sheets-*Sheet 2 Patented Dec. 21, `1926.

UNITED STATES PATENT OFFICE.

LEE R. BUSHYAGEB, F JEANNETTE, PEVNSIYLVANIA.

'xppnation ieanarch 11, 192e. serial No. 93,885.

My invention relates to fans and propellers, and particularly to propellers such as are employed in aeronautics for driving andA and preferably do make provision that, as

the blade angle is changed, the rate at which that angle diminishes from the base outwirdlytoward the tip shall change also; if at the base of the blade the blade-angle vbe large, the warping of the blade shall be relatively steep; if at the base of the blade the hlade-angle be small,-then the warping 'from the base toward the tip of the blade'shall be relatively gentle. My invention further contemplates change in camber; that is to say, in cross-sectional shape of the blade. (f)rdinarily apropeller blade is in cross-sectional shape concavo-convex, the curvature ot the convex surface being on shorter radii than that of the concave surface, and the concave surface constitutes the face of the blade. My invention contemplates the possibility of changing the curvature of the face of .he bladefand, incidentally, of the back ot' the blade correspondingly. The curvature oi the tare of the blade may, within given limits, he increased or diminished, and the blade in cross-sectional shape may become plano-convex or doubly convex, as desired. The accompanying drawings illustrate the invention in application to a propeller for an aeroplane. Fig. I is a view in section, on a plane through the axis of propeller rotation, and showing in longitudinal section one ot' the propellerblades. Fig. II is a view in section, on a plane at right angles to that of Fig. l and perpendicular to the axia ot rotation, and longitudinal with respect to .-he blade. T he plane is indicated at II-II, Fig. I. Fig. II is diagrammatic, in that no attempt is made to indicate in it either bladeangle'or warping; the .showing is as though the blade extended ina plane, perpendicular to the axis of rotation. Fig. III is a view ot' the structure in side elevation. Figs. IV and Y are views in section, on the planes respectively indicated at rv-rv and v- Fig. II. Fig. VI is a diagrammatic showing, and in side elevation, of the assembly of `sparswhich go to make `up a propeller blade.

Figs. VII and VIII show the propeller blade coverincross-section and in elevation and illustrate an incidental detail of structure. Fig. IX is a diagrammaticillustration,of a certain essential detail.

The propeller shaft 1 carries, splined to it, a hub 2. I-Iub 2 is provided with a plurality .of radially opening pockets 3, whose 'general shape and arrangement will be sui- `ciently understood by considering Figs. I,

II, and III. The oriice of the pocket, it will be noted, is in Fig. III shown to extend angularly with respect to la plane perpen-` dicular to the axis of rotation. This feature,

-though not essent-ial'to the invention, will be preferred.

The propeller' blade is compound; it is made up essentially of a plurality of longitudinall extending spars 4. -These spars, mounte y at the base in a pocket 3 of the hub, extend through the orifice in the pocket, and are extensible and retractible in such mounting; and in their extension and retraction, and by the particular means about t0 be de-v scribed, the ends .already indicated are attained.

Within thel pocket the basal ends 41 of So. l1

the spars 4 are strung upon a bar 5, and bar y 5l is mounted by screw-thread connection upon a shaft 6, which shaft with respect to the axis of propeller-rotation extends radially, or substantially so. As shaft 6 vis turned, the bar 5 is moved outward and inward, and the spars 4 are correspondingly extended and retracted. Figs. I'and II show two pockets 3, arranged each diametrically opposite the other, and 'this is a convenient arrangement. In this case a single shaftti, oppositely threaded at opposite ends, may carry in the two pockets twobars 5, and these two bars will in response to shaft. rotation move simultaneously and` oppostely, outward and inward. It will of course be un# derstood that such diametrically o posite ar- In the .orifice of each pocket is set a particularly indicated in F ig.

I cradle 7, adapted to engage (through blocks 9) the edges of the seated s ars an adapted to tip transversely on its caring 71. The opposite rim of the orifice is adapted to engage the opposite edges of the seated spars 4. Preferably ythis opposite rim of the .oritice carries blocks '8. The blocks 8 Aare adapted to tip on their bearings 81 in the direction of the length of the seated spars. Each pair of blocks 8 and 9 engages the basal end L11 of one of the4 s ars 4.' As I, the basal ends 41 of the spars 4 are provided with upper and lower edges which are relatively inclined, and this relative inclination varies as between the spars which-together make up a set. As shown in Fig. VI the basal end of the spar nearest the observer is of diminishing width from left to right, and the end ofthe most remote spar is of increasing width from left to right, and the intermediate spars are in this respect graded from one extreme in vshape to the other. Manifest-lyin this graded succession the base of an intermediate spar will be of uniform width throughout its extent, or substantially The general characterization of the spars as having-angularly disposed opposite edgeswill not on thatI account be misunderstood. A cross-section through the basal ends of the assembled'spars (Fig. IV)-pre sents an assembly of trapezoidal outline, and while on diderent planes of cross-section the opposite non-parallel sides of the trapezoid vary in their relative inclination (on one plane the trapezoid becomes a parallelogram), on every cross-section the area of that trapezoid is constant. As the bar 5 moves out and in extending and retracting the spars 4, cradle 7 rocks transversely on its bearing, and the e'ect is that the component spars of the propeller blade shift relatively, in parallel planes, transverse to the face of the blade. Such relative shifting of the spars effects change lin the bladeangle.

It is referable that the change in bladeangle e ected by the means described should be most pronounced.toward the base ofv the blade and least toward the tip. Stated in other words, it is desirable that as bladean lefincreases, warping should increase; an the blade should approachmore nearly to a plane' surface. This desirable characteristic of .movement I achieve by further refinement of the means which in their more gen-l eral features'have been already described.

. -I.have said of the upperrim of ocket 3- thatit vis advantageous provide with a set -of ti ping blocks 8. Manifestly for pur osea itherto described the bearing of the asal ends4 o'f the spars upon the upper rim of the pocket might be against a transversely extend knife-edge. But, particuas blade-angle diminishes, the face of larly for the further purposes just indicated,

I prefer to employ blocks such as those shown, semi-circular in outline, engaging along their straight edges the edgesof the spar ends and turning in curved seats formed to receive them. The cradle'7 carries a correspondin blocks 9, engaging tie spar ends along their straight edges and ti ping in curved seats formed for them in the cradle. Manifestly if, as the spars move outward and inward, the blocks 9 which they en age be shifted and held in new but unyie ding positions, the range through which the individual spar sweeps may be shifted, relatively to a plane` -perpendicular to the axis of propeller rotation; and when, added to this, the tipping of cradle 7 is taken into account-a tipping transversely, on the bearing 71,-it is manifest that as between the spars which together make up the blade, the effective movement so far as concerns blade shape may bc ymade more pronounced toward the base of the blade and less pronounced toward the tip. -Accordingly, I provide for a proper control of the blocks 9 in Itheir actual and relative positions. The blocks9 are provided with notches 91 which extend from the periphery radially inward. A rod 94 extends when the parts are assembled through the series of notches, and within each notch the rod 94 carries an ,eccentric disk 92, and the disk engages the o posite parallel walls 'of the notch. The rod) 94 beino secure, thel blocks 9 are secure against tipping on their semi-circular seats 73 in cradle 7; and, rod 94 is rotated on its axis the blocks 9 are tipped.I In operation, as each block 9 is tipped, its opposite companion block S tipped, and then, as the spar which lies between moves inward and outward (the transverse tipping of cradle 7 on its-bearing '."1 permitting this), its actual range is changed, relatively to any given plane perpendicular to the axis of propeller rotation. The positions of the cam disksV 92 upon the rod 9-1 am individually adjust-able, but when adjusted the set of `cams'moves as a unit, rotating upon the axisof rod 94. The relative positions of the disks 92 in their. adjustment determines theranges of movement of ad jacent spars in relation one to another.

The rod 94 is journalled for rotation in the end walls of cradle 7 and at one end il is prolonged in a crank arm 93 which enters series of semi-circular a guiding groove '31 in the inner wall of CTI sition of the ranges of movement of adjacent spars; and, as I have said, the adjustment is preferably 4such that as the blade-angleincreases, warping increases. yThe groove 31 1s spiral w1th respect to the axis of tlpping of cradle 7 on its seat 7l, and as this spiral4 in'comparison with Fig. I. It will be per.

ceived that if the lower edge of the basal portion 41 of spar. 4 be engaged by block 9,

-and it at any given instant in operation block 9 be fixed as against tipping in its bearing in cradle 7, then it is the angle at which the lower edge of the base 41 of the spar 4 extends, With-.respect to the mid-line ca of the spar, that is determinative of the range of sweep of the spar in a plane transversesto the face of the blade. And it will further be perceived that accordingly as this angle varies, as between successive spars so the ranges of successive spars will vary in their relative positions ;v and, further, variation here may be such as to eect change in camber.

Turning now to Fig. VI, it will be perceived ot' the collocation*ofwspars there shown, that whereas at the mid-point in the length ot the bases 41 all the spars lie in a lstraight line and inline with the eye, at the extreme right-hand end the succession is not on a horizontal line, nor is the line Straight. The indication is that the middle spar of the series is most steeply inclined from left lto right, and that the spars on either side are inclined at diminishing steepness to the out` Viewed at the end this assembly' er ones. would be seen to be bowed downwardly along the lines defined by the upper and lower edges of the spars. Supposing the assembly to be otherwise such that a straightand unbowed succession would afford the desired shift of blade-angle without change in camblade-angle as the spars are extended and re tracted. Furthermore, if the assembly were such as to produce no change in blade-an-v gle, still the modication here alluded'to would afford change in camber by extension and retraction of the spars, while the bladeangle continued constant. y

rIhe drawings show the spars to be 'tapered, from base to tip, and it will be understood that by the particular relative positions given toy the succeeding eccentric disks 92 on the rod 94, relatively great movement at the bases and relatively little movement at the tips of-the spars, may be attained, thus refining upon both the changes inblade angle and the `changes in cambcr explained above.

To recapitulate, there are twov Variables inthe organization: (l) the relative setting of l the successive disks 92 eccentrically upon rod 94, and (2) the value of the angle which the lower edge of the blade forms with its mid-line. yIVarping may be controlled by the first of thesev variables; camber by the sccond. Underlying both is the characteristic that, given a set of spars withbases of graded angularit-y as between opposite edges, and

given such a set of spars seated in a hubl pocket with the tipping cradle 7 defining one edge ofl the orifice, change in blade-angle may be leffected by the extension and retraction of the assembly of spars. Andlit is a mere matter of proper proportioning, what the range in such blade-angle change may beg-it may, indeed, be reduced-to zero, and will be, in case change in camber alone were in any particular case desired.

It remains to describe the means by which the shaft 6 is rotated, to effect the extension and retraction of spars 4 and the vconsequent changes in blade configuration. Shaft 6 carries a worm gear Wheel 61, and to worm f wheel 61 a worm 62 is meshed. `Worm 62 in y 1- turnY is gearedby such intermediate parts as the other of sleeves 63 and 64 or` to remain Hf free of engagement with either.

So long as the latch 66 continues in the intermediate position shown in Figs. III, IV, and V the sleeves 63 and 64 will be carried without relative movement upon the rotating hub 2; the gearing .described will be at rest, shaft 6 will vnot rotate jand the blade will continue constant in shape. `When, however, the latch 66 is swung to engage one or the other of sleeves 63 and 64, the `roj tation of shaft l will through the gearing lll() described effect rotation of shaft 6 in one v direction or the other. Spars 4 willcorrespondingly be extended or retracted, and the blade-an le change 1n the blade-angle the degree of war'plng will preferably, and by the particular means described, be changed. And, in, addition, and if desired', and by the particular means described, the camber also of the has been altered in the desired manner and to the desired extent, therdriverl shifts the ,willy be changed, and with4 '135 latch 66 to intermediate position'again, and

thereafter the propeller blade remains in the particular shape to which it" has thus been newly brought.

Acn

Fig. Il shows, somewhat diagrammatically, some of the spars 4 which compose the propeller blade vlying closely adjacent one anotherl and others spread apart and with basal ends 4l radiating slightly. Blocks 72 f may serve to maintain them in such position. If that radiating feature be present it is manifest that as the spars are extended not only will the angle, camber, and warping of the blade be changed but the breadth of the blade will simultaneously be increased.

v The blade may consist of the assembly of Lspars and nothing more, or'it may be provided with a cover. The cover, if it be present will be secured immediately to the spars, or its opposite `webs will be so stayed together at intervals as to secure it in place upon the spars, and in an case suitable allowance will be made for c langes in shape of the assembly of spars within the cover.

Figs. VII and VIII show a cover adapted to a blade `capable of being changed in width at the base by means such as have been described, the change in width diminishing outwardly to zero at the tip. The coveris made in two parts 42 and 43, hinged at the tip as at 44 and engaging one another telescopically along their edges. Similarly the cover may be made in sections which telescope longitudinally, and vso'provision may be made for extension and retraction of the blades. Since in Fig. II the spars 4 toward ,the bottom of the figure are shown to be capable of lateral spread, it will be perceived that there vmust be allowance for this within the cover, and particularly. at the -tip of the blade. And upon this point it will suliice to say that the spars will ordinarily taper outwardly and be at their tips flexible in the plane of blade extent.

I claim as my invention:

1. A propel-ler or fan including a hub and a-blade, the blade including in lts structure a plurality of spars extenslble and retracti-v ble relatively to the hub, and means for effecting relative movement of the spars in a direction transverse to the face of the blade, as they are extended and retracted.

2. A propeller including -a hub and a blade, the blade including in its structure a plurality of spars extensible and retractible relatively to the hub, and means for effecting as the spars are extended and retracted rel-` ative movementof the spars in a direction transverse to the facey of the blade, such relative movement being greatest at the base of, the bladeand dimimshing thence outwardly.

3. propeller or fan including a hub and g blade, the blade lncluding in vits structure a plurality of spars extensible and retractible relatively to the hub, and meansfor effecting as the spars are extendedv and re' tracted, both a spreading of the spars laterally and a relative displacement of the spars in a direction transverse to the face `of the blade.

4. A propeller or fan including a hub and a blade,'the blade including in its structure two'spars with'basal portions whose opposite edges. as between the two spars are dissimilar in angular arrangement, the hub being provided with a radially opening pocket in which the basal portions of the said spars arey seated, one of 4the opposlte edges of the orifice of the said pocket bein defined by a cradle engagingthe seate' spars and ladapted to rock in a directionv transverse to the length of the seated spars,

1n a dlrection transverse to the len th of theA spars, and on the opposite side yblocks engaging the seated 'spars and adapted to rock in the direction of the length of the spars, and means for extending and retracting) the said spars in their mounting in the propeller or fan including a hub and nsA 6. A propeller or fan including a hub and afblade, the blade including in its structure two spars with basal portions whose opposite edges as between the two spars aredissimilar in angular arrangement, the hub being provided with'` a radially openin pocket in which the basal portions of sai spars are seated, one of the opposite edges of the orifice of they said pocket' being defined by a cradle provided with a lurality of spar engaging blocks, the said being adapted to rock in a direction transverse to the length of the seated spars, means for effecting relative tipping vin the direction.

of the length of the spars, of the blocks borne bv said cradle, and means for extend ing and retracting the said spars .in their mounting in the hub.

cradle i 7. A propeller or fan including ay hub and. a blade, the blade including in its structure two s ars with basal site edges as between t e two spars are is# similar in angular arrangement, the hub being rovided with a radially opening ocket in w ich the basal portions ofthe saifs are seated, one of the op osite ed es o the orilice of the said pocket eing de ed by a ortions whose op 0'-- cradle adapted to rock in a'direction transverse to the -length of the seated spars, the said cradle carrying wedge-shaped spar- I spacing blocks.

8. A propeller .or fan including a hub and a blade, rthe blade including in itsstructure two'siars with basal portions whose opposite e ges are as between the two spars issimilarin angular arrangement, the hub being provided with a radially opening dpocket in which the basal portions of the sai spars are seated, one of the opposite ed es of the orifice of the said pocket being de transversely rocking cradle provided with two longitudinally tipping spar-engaging blocks, meansl for extending and retractmg n rocking of the cradle for tip said spars are seated and vthe seated spars in their position in the orifice inthe hub, and Ameans for tipping the blocks with which the cradle is equipped, one relatively extended and retracted.

9.1A propeller or fan including a hub and a blade, the blade includin in its structure two s ars with basal portions whose vopposite e ges are asy between the two spars dissimilar in angular arrangement, the hub being provided with a radially openlng pocket in which the basal portions of the said spars turetwo spars with basal portions whose opposite edges are as between the two spars dlssimilar in -angular arrangement, the hub provided witha radially opening in which the'basal ortions of the rom which the s ars protrude, o ne of theop'posite edges of the orifice of the said pocket eing defined b a tranlsversel cradle provided wit two on tu ina y ippin spar-engaging radiall llotted blocks, a rod rotatably borne vbeing p ket byv sai cradle extending through the slots ed by av to the other, as the spa-rs are.

in thesaid blocks vand equipped within each slot withv an eccentrically mounted4 disk, means for extending and retracting the seated spars in their position in said orifice and means for rotating said rod as the spars are *extended and retracted. A f fan including a .hub

11. A ropeller or and a bla4 e, the blade including in its structure two spars with basal portions whose opposite edges are as between the two spars dissimilar i-n angular arrangement, the hub being providedv with a radially openinginterna ly grooved pocket in which the basal ortions' of the said spars are seated and rom which the spa'rs protrude, one of the opposite edges of the orice of the said pocket being defined by atransversely rocking cradle provided with two longitudinally tip'- pingspar-en aging lradially slotted blocks,

a bar rotata ly bornefby said cradle and bearing a crank arm en aged by the groove in the hub, the said ro extending through the slots in the said blocks and equipped within each slot with an eccentrically mounted individually adjustable disk, and means for extending and retracting the seated spars in their position in the said orifice.

12. A propeller or fan' including a hub and a blade the hub being provided with a radially opening orifice whose opposite edges are defined by pairs of tipping' blocks the v set of blocks which form one edge being borne in a transversely' tipping cradle, the blade including in its structure a pluralit of lspars which at -their vbases extendthroug the oric'e in the hub and each spar'between a pair of tipping blocks, the opposite and block-engaged edges ofthe bases of successive spars being vlisposed at varying angularit means for controlling the tippingof the locks which constitute the set on one side of the orifice, the edges of the bases of successive spars which engage the blocks so controlled being disposed at varyingv angularity with respect to the mid line yof the spar, 1 and means for extending and .re-

tractmg the seated spars in their position in the said orifice.

In testimony whereof I have hereunto set 

